"One or other of us will have to go," Oscar Wilde is supposed to have said on his deathbed to the hated wallpaper in his room. The perilous acceleration of Arctic ice loss, and the imminent threat of irreversible climate change poses a similar ultimatum to the economic system that is pushing us over the brink. For society's sake I hope this time we redecorate.

Fortunately, many people are queuing up to propose better designs, rather than just cursing the interiors, as you can read about here.

Monday 1 October marks the halfway point in a 100-month countdown to a game of climate roulette.

On a very conservative estimate, 50 months from now, the dice become loaded against us in terms of keeping under a 2C temperature rise. This level matters because beyond it an environmental "domino effect" is likely to operate. In a volatile and unpredictable dynamic, things like melting ice, and the release of carbon from the planet's surface are set to feed off each other, accelerating and reinforcing the warming effect.